2009 KLX250S, 351 big bore kit installed, all OK. On the left side there is a very slight amount of oil coming out of the hole in the block. Only 20 miles on the kit, still breaking it in. Normal? What is that hole there for anyway?

Mixk

 

We might need a little more detail on the specific hole you're referring to and your definition of "block". There is a "hole" in the left side of the cylinder head that is a drain hole for the spark plug cavity. If oil is seeping through that hole, I'd suspect a valve cover gasket leak. Just speculation, however, without more detail.

 

OK, that's the hole I am talking about., I had to get a new valve cover gasket, the old one would not fit, they shrink? I guess. The oil is just the residual oil that leaked when I tried to use the old gasket. The New one was not cheap either. Thanks for the info.
Time to put on more break in miles.

 

You must have an '09 or early '10? Those models tended to have the shrinking valve cover gasket.

I suggest cleaning the oil out of that weep hole. You don't want it gathering dust and plugging up as you want water that collects in the spark plug depression to weep away and out that hold.

 

 

Yes, mine is an 09. Any recommendations on carb jets? At some point I will give it a pumper carb, not sure which on is the best to go with. I did clean out the drain hole, no more oil is coming out. Just did 100 miles and put in new oil and filter, wring it out tomorrow.

Mick